                            :subcat {:3 {:sem {:obj subject-semantics}}}}}))
         
         sentential-adverb it-pos/sentential-adverb
+        subj-obj-humanness
+        (let [human (atom :top)]
+          {:synsem {:sem {:subj {:human human}
+                          :obj {:human human}}}})
         transitive it-pos/transitive
         verb-aux it-pos/verb-aux
         verb-subjective it-pos/verb-subjective]

        intransitive-unspecified-obj it-pos/intransitive-unspecified-obj
        masculine-noun it-pos/masculine-noun
        non-comparative-adjective it-pos/non-comparative-adjective
                                       
        preposition (let [shared (atom :top)]
                      {:synsem {:cat :prep
                                :sem {:obj shared}

       :synsem {:sem {:pred :be}}}

      ;; essere: copula ;; note that we don't enforce agreement the same here as we do in essere-adjective: TODO: try to make more consistent.
      {:unify [transitive essere-common gender-and-number-agreement-1 subj-obj-humanness]
       :notes "copula" ;; significant only for debugging.
       :synsem {:cat :verb
                :subcat {:1 {:cat :noun}
                         :2 {:cat :noun
                             :pronoun {:not true} ;; accusative pronouns cause unbounded depth-first searches on the subject side. (TODO: not sure if this problem is still present)
                             :def {:not :demonstrativo}}}
                :sem {:pred :be
                      :activity false
                      :discrete false}}}

      ;; essere: intensifier
      ;; this is for e.g "essere più alto di quelle donne belle (to be taller than those beautiful women)"
